Network function virtualization (NFV) allows traditional network equipment dedicated to one or more particular network functions to be virtualized using a general-build hardware platform to provide cost reduction, operation efficiency and agility. In general, NFV separates network functions from the hardware they run on through a virtual hardware abstraction. By way of example, an NFV framework has been developed by the European Telecommunications Standards Institute (ETSI) NFV Industry Specification Group (ISG).
At run-time, virtual network functions (VNFs) can be created by instantiating virtual network function (VNF) software on one or more NFV hosts. Connectivity can be established between the VNF instances to implement a network as though the network were implemented with traditional network equipment. This can be accomplished using the VNF deployment and operational information captured in a VNF descriptor (VNFD), as well as additional run-time instance-specific information and constraints.